Claude Opus 4.5vsGrok 4.1 Fast

Claude Opus 4.5
Grok 4.1 Fast
Benchmarks
Nonsense detection
BullshitBench v2
90%Best
19%
Coding
SWE-Bench Verified
80.9%
Science
GPQA Diamond
87%
Overview
CompanyAnthropicSpaceXAI
Release dateNov 24 2025Nov 19 2025
AccessProprietaryProprietary

Which is better: Claude Opus 4.5 or Grok 4.1 Fast?

Claude Opus 4.5 leads Grok 4.1 Fast on 1 of the 1 benchmark they both report (BullshitBench v2). Grok 4.1 Fast shipped 5 days before Claude Opus 4.5, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

On BullshitBench v2, Claude Opus 4.5 leads at 90% vs Grok 4.1 Fast at 19%.

Frequently asked questions

Claude Opus 4.5 was released by Anthropic on Nov 24 2025.

Grok 4.1 Fast was released by SpaceXAI on Nov 19 2025.

Other comparisons